Continuing demand for advancement of electronic devices motivates improvements in durability and portability. These devices may include cell phones, smart phones, tablet computers, laptop computers, wearable devices, navigation devices, sports devices, accessory devices, or other similar products. Many of these portable electronic devices may include internal batteries which may be charged through a connection to an external direct current power source from time to time. An external power source connection may often require two or more exposed electrically conductive contact areas which mate with a respective one of an electrically conductive contacts associated with the external power source.
As the device is introduced to diverse environmental conditions, the electrically conductive contacts may be exposed to liquids or humidity. In some circumstances, an electrically conductive contact may be exposed to an electrolyte (e.g., by immersion, condensation, etc.) which may facilitate an oxidation-reduction reaction on the surface of the contact when a direct current bias is applied to the contact. After extended periods of use without proper cleaning of the contact surface, the electrical contacts may corrode. In other examples, galvanic corrosion may also occur between the external contact and the internal contacts. In either case, corrosion may decrease the charging efficiency of the device or may prevent the device from being charged at all. In certain cases, corrosion may become so advanced that a device must be repaired. Repairs may be costly and frustrating to users.
In other cases, dendrites may form along the edges of a contact exposed to moisture and an electrical field. Such an environment may encourage metal ions to migrate and congregate, forming dendrites at locations along the perimeter of the contact. After a time, these dendrites may form an electrical connection between adjacent electrical contacts, negatively interfering with device operation or potentially irreparably damaging the device.
To mitigate these issues, external contacts may typically include a corrosion-resistant coating to the exposed exterior surface. For example, some contacts may be electroplated with corrosion-resistant metals such as gold or platinum. Other examples include contacts with coatings that may be electrically conductive and corrosion-resistant. Although temporarily effective, such coatings are subject to frictional wear and may become less effective over the life of a device.
Furthermore, present demand for electronic devices of smaller size has necessitated a corresponding decrease in the space a charging port may occupy. As a result, charging contacts within charging ports have also decreased in size and have been positioned closer together. This in turn may increase the possibility that even minor corrosion or dendrite growth to the conductive contact areas may have a major effect on charging efficiency, device lifespan, and overall usability.
Accordingly, there may be a present need for improved methods or apparatuses that prevent or substantially inhibit corrosion and dendrite growth on externally exposed electrically conductive contact areas that does not rely on corrosion-resistant coatings.